They had been talking, it seemed, about Jesus Christ. The fact was that the editor had commissioned the poet to write a long anti-religious poem for one of the regular issues of his magazine. Ivan Nikolayich had written this poem in record time, but unfortunately the editor did not care for it at all. Bezdomny had drawn the chief figure in his poem, Jesus, in very black colours, yet in the editor's opinion the whole poem had to be written again. And now he was reading Bezdomny a lecture on Jesus in order to stress the poet's fundamental error.
It was hard to say exactly what had made Bezdomny write as he had--whether it was his great talent for graphic description or complete ignorance of the subject he was writing on, but his Jesus had come out, well, completely alive, a Jesus who had really existed, although admittedly a Jesus who had every possible fault.
Berlioz however wanted to prove to the poet that the main object was not who Jesus was, whether he was bad or good, but that as a person Jesus had never existed at all and that all the stories about him were mere invention, pure myth.